Subfloor Preparation



• The floor preparation is just as important as Installing the floor itself. Improper floor preparation can cause defects and problems within the hardwood floor. The problems may not be noticeable right away and might not show up until a few weeks or months after the installation. Your Hardwood floor may detach from the sub floor and start to make strange squeaky noises and sounds. • Improper glue down preparations will result in continuous popping sounds. Improper nail down preparations will result in constant squeaking and popping sounds. A poor floating floor preparation will result in an immediate squishy feeling beneath the hardwood installation. First Steps In Floor Preparation for Hardwood Flooring Installation • The first step for any sub floor preparation is to clean out everything in the installation area. Any furniture or objects that cover the sub floor must be removed, such as cabinets, tables and chairs. You will probably have to remove the molding, the base boards and sometimes the door. You might want to remove your exiting floor, depending on what kind of flooring style you are going to install. Solid hardwood floors, for example, must be installed on a wooden sub floor. Engineered hardwood floors can be installed on concrete, vinyl and wooden sub floor surfaces. Making it the most flexible to install out of all the hardwood styles. • Another important task you MUST do prior to the installation, is to let your new hardwood floor planks openly sit in the installation area, so the hardwood can acclimate to the temperature and humidity of the room. We recommend opening the hardwood floor boxes in the installation area (or in a room with similar levels of humidity) and let them acclimate for at least 72 hours before the installation. It's important to keep the relative humidity of the installation area between the levels of 45%-65% percent during the installation process. You may use a heating or air condition system to preserve the desired humidity. Floor Preparation With Wood Sub Floor • A wooden sub floor must be cleaned from any waste, grease, paint, oil or debris. It is important to make sure that the wooden sub floor is structurally sound and perfectly clean. You must nail, screw or staple any squeaky or loose areas. Replace any damaged sub floor, do not leave it untreated. The minimum thickness required for a plywood sub floor is 5/8”. We strongly recommend using a 3/4” plywood thickness. Plywood sheets should be laid out with grained outer plies that are at a perpendicular angle to the floors joists. • The moisture content within wooden sub floors is very important. Moisture levels mustn’t exceed over 16% ! You can use a Moisture Meter to check the moisture level within your wooden sub floor. • The next step in the preparation process is to check the flatness of the wooden sub floor. The sub floor must be flat and free from any nails or staples. The height variation cannot be larger than 1/8” over 6'. You must sand the high spots and fill in the lower ones. We recommend using an Edger Sander, for it can run in a small, dense sub floor and target the desired area. (A proper Floor Preparation is 100% Necessary for a successful Hardwood Floor Installation !) Floor Preparation with Concrete Sub Floor • Just like a wooden sub floor, a concrete slab must be cleaned from dirt, grease, paint, oil or any other debris. Cracks within the concrete slab must be filled with the appropriate materials. The concrete slab must be flat and smooth with no high and low spots. High spots must be sanded down so that they are even with the concrete slab. Low spots must be filled with cement based material or a self leveling cement with density of at least 3000 PSI. The variation must be lower than 1/8” over 6’ of concrete. • Concrete slabs must also be checked for their moisture content prior to the hardwood floor installation. Moisture levels must not exceed 14% percent of moisture. You can use a Moisture Meter to test the moisture within your concrete slab. If moisture is present you will have to run another test called Calcium Chloride and pH Alkalinity Test. This test is used to determine the moisture emissions of the concrete and the alkalinity present in the concrete slab. The maximum acceptable level for the Calcium Chloride test is 3-lbs./24 hours/1000-ft sq. for moisture emissions. As for the pH Alkalinity test, a reading of 6-9 on a pH number scale of 1-14 is acceptable. • DO NOT INSTALL your hardwood floor on a concrete slab if you are receiving high readings on your Calcium Chloride and pH Alkalinity test. You must use a specific Sealer in order to correct the humidity and calcium levels within your concrete slab. • Another important fact to know, is that Solid Hardwood Floors cannot be installed directly over concrete slabs. In order to prepare the concrete slab for a solid hardwood floor installation, you must install a minimum thickness of 3/4'' plywood with a minimum of 6 millimeter poly film vapor barrier paper. • Introduction to Installation